The present invention relates to a mechanism for drilling holes, specifically aerospace and aircraft structure holes. More specifically, the present invention relates to a portable numerically controlled (N/C) water-jet driller.
Aerospace and aircraft structures contain numerous pre-drilled holes, specifically fastener holes, which are drilled through the skin and substructure. These holes must be accurately located and have excellent finish quality in order to meet the stringent requirements necessary for structural fastening in aircraft and aerospace applications.
Current hole drilling devices pose several problems and difficulties. These problems include slow drilling rates, mislocated hole position, and high capital and facilities costs. These drilling devices include N/C drill towers, pneumatic feed drill motors and backup-tooled drilling machines.
N/C drill towers are numerically controlled drilling machines that are large, vertical mills on massive tracks that drill fastener holes in airframe structures. Several brands of N/C drill towers are available, such as the Jobes(trademark) driller (known as the precision drill center), which is currently utilized to drill F-22 wing skins. Though highly accurate, these machines have slow drilling rates, while requiring large capital investments and extensive facilities modifications. Drilling rate is typically defined, but without limitation, as the quantity of holes that can be drilled per hour (including time allocated for part fixturing, driller alignment, teardown and maintenance.) The drilling rate with N/C drill towers is further reduced when structural deflection caused by drilling forces acting against the structure being drilled limits the drilling force that the machine can impart to the structure being drilled (thereby limiting drilling rate).
Pneumatic feed drill motors are devices that are hand aligned into drill guides or drill templates that position the drill motor over the intended hole location. Typical models utilized on an aerospace or aircraft production floor are the Spacematic(trademark), Peck(trademark), and Quackenbush(trademark) drill motors. Pneumatic feed drill motors suffer from slow drilling rates, mislocated and poor quality holes.
Backup-tooled drilling machines are numerically controlled and can drill accurate, high quality holes. These machines also have fast drilling rates because the high drilling forces are nullified by a movable backup structure that is repositioned for each hole by the drilling machine. Production backup-tooled drilling machines include the Electro-impact(trademark) (used on the Boeing 737(trademark)) and Flexible Assembly System (used on the Boeing F/A-18E/F). The primary limitations of this type of driller are high capital costs, high maintenance costs, excessive floor space, U and O costs, and long procurement and facilities lead times.
Other types of drilling machines or methods such as high power lasers that remove material with heat or thermal energy, cause mechanical stresses on the cut surface and can emit hazardous materials or vapors.
For the foregoing reasons, there is a need for a new portable N/C water-jet driller.
The instant invention is directed to a portable N/C water-jet driller that satisfies the needs enumerated above and below.
The present invention is directed to a portable N/C water-jet driller. The portable N/C water-jet driller includes an agile water-jet driller end effector and a numerically controlled apparatus for placing the water-jet driller end effector within a region of the hole to be drilled. The agile water-jet driller end effector communicates with the numerically controlled apparatus.
It is an object of the invention to provide a portable N/C water-jet driller that can drill fast, accurate, high quality holes with reduced capital, maintenance and facilities costs.
It is an object of the invention to provide a portable N/C water-jet driller that does not require excessive floor space.
It is an object of the invention to provide a portable N/C water-jet driller that improves the assembly process, particularly the assembly process of aircraft, by greatly reducing the drilling forces required to create fastener holes.
It is an object of the invention to provide a portable N/C water-jet driller that does not require an indexing tool. Indexing tools are typically defined as hard templates or drill guides that guide the location of the hole on the structure being drilled.
It is an object of the invention to provide a portable N/C water-jet driller that combines the invasive drilling capability of a water-jet cutter with the labor savings of a numerically controlled machine.
It is an object of the invention to provide a portable N/C water-jet driller that does not utilize or emit any noxious gases or liquids and does not create hazardous materials or vapors. It is another object of the present invention to provide a portable N/C water-jet driller that removes material using a non-thermal process.
It is an object of the invention to provide a portable N/C water-jet driller that allows most fixturing tools to be eliminated because the driller imparts virtually no deflecting force during drilling. Fixturing tools are rigid devices that are usually permanently floor mounted that have precisely machined features that captivate or clamp structural components into precise 3-dimensional orientations. Generally, lower drill forces allow for small, lightweight, less expensive fixturing tools.
It is an object of the invention to provide a portable N/C water-jet driller that does not leave any heat-affected zones or mechanical stresses on the cut surface.